By Teresa Rivas

Shares of Monster Beverage (MNST) were dropping 4.2% in recent trading, on news that physicians may potentially endorse a ban on energy drinks for children.

The American Medical Association’s House of Delegates, its principle policy-making body, is set to debate high energy drinks at a meeting this weekend. This has investors concerned that the medical body may endorse at least a partial ban on the advertisement and/or sales of energy drinks to anyone under the age of 18.

Of course, Monster and its peers have thus far easily shrugged off health warnings about highly caffeinated energy drinks: Last week, Monster said that gross sales rose a combined 9% year-over-yea in April and May. International sales climbed 17% in those months.

Nor has Monster’s popularity has been hurt by recent investigations in San Francisco and New York, and a lawsuit in Maryland. Federal regulators are also investigating the industry as a whole, to determine whether energy drinks pose health risk if consumed in excess or by vulnerable consumers, like children and adolescents.

Nonetheless, any move that the AMA may make to support a ban could come as a blow to energy drink sales and Monster’s stock price, given the organization’s considerable influence.

Monster’s shares are up about 13.5% year-to-date, even with today’s slide, but are still in the red for the past year, to the tune of 21%.

In early May, the company fell after its first-quarter earnings and revenue disappointed.

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